158 



Mycologia 



Conidial Formation 

 At the initiation of the formation of the hyaline conidia, the 

 distal end of the conidiophore is filled with protoplasm of a high 

 refractive index, and contains a number of oil globules (Fig. n) 

 and sometimes small vacuoles. The basal portion may be oc- 

 cupied by a large vacuole surrounded by a thin layer of cyto- 

 plasm (Fig. ii ). Shortly after a conidiophore has reached 

 mature size, examination with great magnification ( X 2270) 

 shows that its apical portion contains a fully formed conidium 

 which has a distinct wall. This conidium is separated from the 

 protoplast and wall of the conidiophore by a distinct line in such 

 a manner that the wall of the conidiophore appears as a closed 

 sheath about the conidium (Figs. 8, 9). This line of sepa- 

 ration is visible when living specimens have been stained with 

 saf ranin and the protoplast has been slightly plasmolyzed. When 

 preparations are made in this manner, the protoplast takes the 

 stain and the wall of the conidium and of the conidiophore 

 remains clear. When the protoplast has not been plasmolyzed, 

 however, the lateral conidial wall is pressed so closely against its 

 sheath as to make the line of separation entirely invisible (Fig. 

 10). However, the line delimiting the basal wall of the conidium 

 from the wall clothing the end of the protoplast of the coni- 

 diophore can at this time be discerned plainly. At each end of 

 this line, a wedge-shaped opening caused by the convexity of the 

 end of the protoplast and of the opposed newly formed conidium, 

 is clearly seen. The size of this space depends upon the pressure 

 exerted by the growing protoplast against the conidium above. 

 When the pressure is great, the end of the protoplast is flattened 

 against that of the conidium and the wedge-shaped space reduced 

 (Fig. 8-10). In case the line separating the conidium from its 

 sheath was visible, it is represented by a solid line (Figs. 8-10), 

 otherwise, by a broken line. Other conidiophores are not un- 

 commonly found whose distal ends contain a second fully formed 

 conidium just below the first (Fig. 8). No more than two 

 conidia within the sheath, however, have been observed. Careful 

 examination of the free end of the sheath containing these conidia 

 (Figs. 8, 9) shows that it is still intact and that the two conidia 



